This invention relates to labels and more particularly to multiple layer labels for application to curved or non-planar surfaces, and methods for making such labels.
The application of single layer labels to curved or non-planar surfaces is an old expedient. More recently, the use of multiple layer labels has been desired. When multiple layer labels are manufactured in-line or in cut sheet processes in generally flat format, their subsequent application to a curved or non-planar surface presents problems. When two adjacent flat labels are applied around a curved or non-planar surface, the outer layer is formed about one outer radius and the inner layer about a shorter inner radius. The differences in these radius dimensions can cause stress and other phenomena within the label structure which act to produce undesirable results in the label.
For example, the outer layer can be unduly stretched to disadvantage such as cracking, tearing, graphic malformation and the like. The inner label can be compressed or bunched, causing it to wrinkle, deform or produce otherwise undesirable aesthetic or physical configurations. Adhesion to the target can be adversely affected. Accordingly, it has been one objective of the invention to provide an improved multiple layer label for application to curved or non-planar surfaces.
Another objective of the invention has been to provide an improved multiple layer label supply with labels particularly useful for application to curved or non-planar surfaces.
Another objective of the invention has been to provide a method for the manufacture of multiple layer labels which facilitates this application to curved or non-planar surfaces.
A further objective of the invention has been to provide apparatus for making multiple layer labels configured for application to curved or non-planar surfaces.
To these ends, a multiple layer label according to one embodiment of the invention comprises a base label, an upper label and an overlaminate disposed over the upper label and holding it onto the base label wherein the overlaminate and upper label are attached at their ends to the base label, but in a central portion are arched away from or spaced outwardly from the base label. When the base label is wrapped or placed onto a curved or non-planar surface, both the base label and the upper label and overlaminate wrap around the surface with the arched portion accommodating the wrapping movement so no undue stresses are placed on the upper label and so the base label is not wrinkled. The preferred embodiment of the label structure thus includes an upper label and overlaminate which is pre-curved to facilitate application of the entire label structure to a curved or non-planar surface.
Other alternative embodiments are contemplated. For example, it may be desirable to provide an arched or pre-curved upper label, without any additional layer, such as an overlaminate, on a base label. Also, it is contemplated that the upper label may include multiple upper labels, all of which are pre-curved or arched on a base label.
Preferably, a trailing edge tab is provided on the upper label layer for release of at least one end of the upper label from the base label when in use and subsequent resealing thereon.
In preferred methods and apparatus of producing a pre-curved label structure according to the invention, an in-line press is modified to incorporate a pre-curve station. Alternately, the invention contemplates use with other forms of web presses. For example, upper labels are held on a base label layer web by an overlaminate extending beyond both leading and trailing edges of the upper label. A lift-up tab is attached to the trailing edge of the upper label layer by an intermediate portion of overlaminate, which also adheres the upper label to the base label layer.
The labels are then reversed in direction and drawn about a forming roller surface having a radius preferably about the same effective radius as the non-planar target surface. This causes the trailing edge of the upper label (overlaminate) to lift off the base label web). Other rollers with radiuses different from the target surface may be utilized to effect the invention. This wrapping around the forming roller surfaces thus breaks the adhesion of the intermediate overlaminate to a release coat area of the base label layer and it lifts and translates forwardly, the upper label and overlaminate lying outwardly of and in contact with the base label. A nip roller opposing the forming roller reattaches the detached portion base to the base label layer.
When the web direction is again reversed and the base label layer flattened out, the upper label layer and laminate curve or arch outwardly on the base label layer. Thereafter, the base labels are die cut on the base liner and the pre-curved upper labels on the base labels are stored or are applied to a curved or non-planar surface.
In this regard, the label structures of the invention, except for the pre-curve structure and method, are like those described in U.S. patent application Ser. No. 09/266,638 filed Mar. 11, 1999 entitled MULTIPLE LAYER LABELS AND METHODS and expressly incorporated herein by reference as if fully and expressly set forth herein. The pre-curve station described herein is added to the apparatus of that patent in-line and at a point just prior to the die cutting of the base labels from the base label layer or web, and removal of the waste matrix.
The structure of the pre-curved label described herein is highly useful in providing an aesthetic, multiple layer label for use on curved or non-planar surfaces and without the stress, cracking, splitting or bunching of typical multiple layer labels when applied to such surfaces.
Moreover, the method and apparatus for producing such pre-curved labels is simple, inexpensive and useful in-line so that the entire label supply can be formed all in-line without intermittent operation or other stoppages. The pre-curve arch in the upper label is formed in them continuously and without treating the structures in any off-line equipment.